Pile fabrics have now achieved a wide degree of public acceptance which is due, to some extent, to their luxurious hand, appearance and warmth. However, up to the present time, one important factor which has inhibited an even greater demand for such fabrics has been the lack of a wide selection of designs particularly, sculptured designs and sculptured multi-colored designs, as compared with the large variety of designs available in other fabric constructions. It appears that the problems associated with the production of interesting, deep, clearly delineated and reproducible designs is that, up to the present time, it has been difficult to produce such desirable designs in a simple but yet inexpensive manner. Consequently, low-cost pile fabrics have generally been esthetically monotonous and uninteresting.
Further, while a number of different procedures have been employed in an attempt to produce pile fabrics having indented designs of various types, such procedures have been objectionable. In one procedure, pile fabrics having designs in the pile formed by fibers of different height have been produced by handsculpturing techniques using, for example, electric shears. Obviously, such a method is unsuitable for large scale production, is subject to inaccuracy and the cost of production, when compared with more mechanical embossing operations, is rather high. Another method for producing embossed pile fabrics involved spinning heat-shrinkable fibers with other textile fibers, weaving the pattern design into a pile fabric using the blended fibers in the pattern area followed by the application of heat to the pile fabric so as to shrink the fibers in the pattern area. Such a procedure is disclosed in U.S. Pat. No. 2,857,652 wherein external heat is used to shrink pile fibers so as to create an artificial fur. Then, in U.S. Pat. No. 2,988,800 a pile fabric containing, in part, shrinkable fibers had its back colored in a pre-determined color pattern. The specific degree of heat absorption of the backing varied in accordance with the color pattern. When heat was applied to the back portion of the fabric, the fibers on the face of the fabric did shrink according to the degree of heat absorption of backing in each color area.
Still another method for producing a pile fabric characterized by a plurality of heights of pile tufts or fibers in the finished article is described in U.S. Pat. No. 2,110,867. In this patent, a pile fabric having a wool or mohair pile is impregnated, in pre-determined pile areas, with a paste containing preferably, calcium thiocyanate. Other materials such as barium, lithium or ammonium thiocyanate were also used. Further, instead of calcium thiocyanate, other suitable materials such as sodium or potassium hydroxide could be used. The paste is applied by use of a print roller, screen, stencil or by block printing. The fabric is then steamed and the fibers shrink in the impregnated areas. Other procedures for producing designs and patterns on fabrics are disclosed in U.S. Pat. Nos. 2,069,760, 2,267,790 and 3,567,548. In these last mentioned patents, a composition is applied to the face of the fabric so as to destroy specific types of fibers in selected areas. In such procedures, no shrinkage is involved.